Tetzlaff plays a contemporary violin by Stefan-Peter Greiner which he has had since 2002, preferring it to his previous Stradivarius instrument. He uses a Peccatte bow, and Vision strings by Thomastik-Infeld in Vienna.[9] He eschews routinely playing the violin with the full, lyrical sound preferred by many of his contemporaries, telling The New Yorker: "The listener loses the ear for the most beautiful sounds if they've been used for arbitrary, non-important things".[1] This approach has occasionally left Tetzlaff open to criticism. The Guardian's critic Andrew Clements argued that his recording of the Schumann piano trios, mentioned above, lacked "any sense of involvement or affection for the music", and that his 2014 release of Shostakovich's violin concertos was sometimes devoid of "character".[1][10]

Tetzlaff suffers from neurodermatitis in his left hand, which can cause extreme pain when the hand's fingers are applied to the strings of a violin. Over the years he has managed the condition in a variety of ways, including by using cotton thimbles to cover his fingers, and more recently by increasing his blood circulation by exercising before performances.[1]